Looking over the htmlbars library, it appears that @mixonic and @munn have implemented features that replace the bind-attr helper. However attempting something like this in Ember Canary results in an error:

I’m assuming these features from htmlbars just haven’t been integrated into Ember yet.

I’m working on producing some Ember screencasts and I’m wondering if there are any branches I could use to get this functionality today. Otherwise I’m wondering how much effort would be needed to get these features in Ember (offering to help if I can). Is this going to be a later Ember 2.0 feature?